Would you eat only through a feeding tube inserted in your nose? As unusual (and inconvenient) as that sounds, the feeding-tube diet, also known as the K-E diet, is the latest fad among brides who are looking to slim down before their big day.

The diet trend employs the same kind of feeding tube that doctors use in the hospital to nourish psychiatric patients who refuse to eat or those with physical conditions that prevent them from eating normally; coma and stroke patients depend on feeding tubes to survive, for instance.

For weight-loss purposes, you don’t need to be hospitalized, but you do have to live with a nasogastric tube inserted through your nose and threaded into your stomach. A protein pack “feeds” your body through the tube, by dispensing drops of a liquid mix of nutrients — but no carbs — totaling about 800 calories a day. Experts recommend that healthy adult women consume about 2,000 to 2,400 calories daily.

People use it drop significant amounts of weight or just to trim off a couple of extra pounds before a big event. “At first I decided not to do it for people who just want to lose a few pounds,” Dr. Oliver Di Pietro, who offers 10-day versions of the diet for $1,500 at his Bay Harbor Islands, Fla., office, told the New York Times. “But then I thought, why should I say 5 or 10 pounds are not enough? People want to be perfect.”

Medically speaking, the diet works by thrusting the body into the first stages of starvation. When you cut calories that drastically, the body responds by going into a state of ketosis, in which it starts to burn stored fat rather than consuming sugar to keep normal body functions going. In fact, each night, as you sleep, your body goes into a mild state of ketosis (which may explain in part why people who don’t get enough sleep tend to be heavier). However, if this process is intentionally triggered, as with a severely calorie-restricted diet, the process can start to eat away at muscle.

Doctors prescribing the feeding tube diet say they don’t let their patients get that far. Di Pietro says he monitors his patients for possible side effects, which include constipation, dizziness and bad breath.

Dr. David Heber, director of the UCLA Risk Factor Obesity Program, says complications can also include aspiration, infection of the lung, kidney failure and erosion of tissues in the nose and throat. “People are taking an unnecessary medical risk by putting in a [feeding] tube,” he says. “To do it for no reason seems to me overly risky. Without medical supervision, if the protein and electrolyte levels are not monitored, it’s not safe.”

You shouldn’t need a doctor to tell you that, but the K-E diet is starting to catch on in the U.S. anyway — it’s been available for years in Italy and Spain, and was introduced in England last year — because it works. Some ads claim that feeding through a tube can lead to a 20-lb. weight loss in 10 days. But the fact that women are dropping pounds by starving themselves is no surprise: whenever you cut calories and deprive your body of food, you’ll lose weight.

The more serious question is what even brief exposure to ketosis does to the body long-term. By causing so much weight loss so quickly, the diet may lead the body not only to drop fat but also to lose muscle mass. But when dieters come off the tubes, the weight they gain back — and they’ll gain it back — will tend to return as fat. As far as weight loss goes, says Heber, the diet will do nothing for you long-term, since the change in how much you eat lasts only as long as you use the feeding tube.

It’s easy to see how ripe the K-E diet is for abuse. It won’t take long before some unscrupulous doctors start offering the tubes with less-than-adequate supervision, and patients start pushing their calorie intake ever lower, stressing the body’s metabolic system with too many dips into the dangerous ketosis zone. That may make it difficult for even healthy eaters to come back to a normal weight if they’ve undergone repeated cycles on the tube. “To try this to get into a wedding dress is extreme,” says Heber. “What really matters is long-term eating habits.” Exactly — the kind that, like a marriage, should last a lifetime.

Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.